Alignment rod



July 5, 1960 F. D. co'rrERMAN ETAL 2,943,381

ALIGNMENT ROD Filed March 26, 1956 q fer6@ I @dier Jl United `States te ALIGNMENT ROD Frank D. Cotterman, L'a Grange, Donald R. Sterba, Westchester, and Walter J. Knorowski and Arthur M. Olsen, Chicago, Ill., assignors to Crane Co., Chicago, Ill., a corporation of Illinois e Filed Mar. 266, 1956, ser. No. 574,044

- 12 claims. (c1. zii- 1.1)

This invention relates to a novel alignment'rod for eiiecting gun barrel 'assemblies and the like. More particularly, it is concerned with an alignment rod suitable for making progressive-twist rifled gun barrel and liner assemblies.

At the outset, in order to obtain a better appreciation of the merits of this invention, it should be understood that prior to this contribution it was necessary when manufacturing progressive-twist riied gun barrel assemblies to either rie the entire assembly after Vinserting the liner or else to pre-rifle the recessed barrel and then rifle the liner` after it had been inserted into the barrel. It must be appreciated that both of these methods involve difficulties, the iirst, because of the problems inherent in rillingV two dissimilar metals with the same cutting tool, and the second, because of the serious problems encountered in aligning the riiiing cutter accurately with the pre-rifled portion of the barrel.

Therefore, it is one'of the more important objects of this invention to overcome these diiiiculties by enabling a pre-ried liner to be inserted into a pre-rifled barrel, with substantial 'convenience and high degree precision in such positioning of the liner.

It must also be understood in considering the real merits of this"contribution that a conventional onepiece assembly mandrel as heretofore used cannot be applied conveniently in the assembly of a liner with a barrel having progressive twist riding, because it would be impossible to remove the mandrel Vfrom such barrel after the liner and barrel assembly has been completed becauseV of the differences or variations necessarily extant in the angles of twistof progressive rifling at the various locations along the length of both the barrel .and the liner.

The novel tool of this invention overcomes such inconvenience and expense as will hereinafter be clear.

tool.

Fig. 5. is a sectional view taken on the line 5 of Fig. 4.

Fig. 6 is a sectional view taken on the line 6 6 of Fig. 4.

Fig. 7 is a sectional view Vtaken on the line 7`7 of Fig. 4 in the same .plane as Fig. 5, but looking in an opposite direction.

Fig. 8 is a fragmentary exterior view of an intermediate portion of the rod assembly."

Similar reference numerals refer to similar parts throughout the several views.

Referring now to Fig. l, there is illustrated a gun barrel generally designated 1 in which one end portion of the barrel is progressively-twist ried as at 2 and in which the opposite end thereof as at 3 the barrel is bored to receive the pre-rifled liner 4 under conditions of assembly hereinafter to be described in greater detail.

At an extreme end portion thereof the liner 4 is lianged as at 5 for its assembly and attachment with the barrel and a weld 6 is subsequently applied to hold the liner in predetermined position within the gun barrel 1. In making the said assembly of the liner 4 with the gun barrel 1, it will be appreciated that the barrel is preliminarily heated to a predetermined temperature by any suitable heating means (not shown) in order to expand the barrel member and thereby permit expansion of the chamber defined by its bore 3 to receive the liner 4. The actual assembly is preferably done by means of a suitable driving means such as a press, not shown, actuated, for example, by means of a hydraulic cylinder in Vwhich the barrel is positioned over the preferably stationary liner 4, while at the same time the barrel is being guided and rotated for structural reasons hereinafter apparent along the rifling 7 within the interior of the barrel and in a manner hereinafter to be described. The overall desirable result is that the riing 8 of the liner becomes complementary to `and is contiguous with the rifling of the barrel.

It has been discovered *that when such relative positioning after suitable rotation of the liner and its telescoping positioning relative to the barrel is accomplished, the accuracy of such positioning is greatly facilitated by the positive guide means for effecting the positioning of the barrel relative to the liner. Specifically, novel means on the tool or alignment rod longitudinally in spaced apart relation kengage the respective riing of the barrel and when the latter is ultimately positioned Within the barrel.

In the alignment tool of this invention, it will also be apparent that a readily assemblable and quickly disassemblable structure is provided employing spaced-apart riing engagement means to attain the above objectives.

Serving initially as the basis for a support for the liner and later also for the barrel when it is finally positioned With respect to the liner, a split clamp generally designated 9 is used and is held in suitably iixed position axially with respect to the rod assembly 11 by such means as the Allen-head screws 12 and 13. For elfecting a more irm engagement of the anged end 5 of the liner, the oppositely disposed clamp members 14 and 15 may be employed.

As previously referred to, it has been found desirable in order to match the respective riiiing of the barrel with the liner, to employ a plurality of radially extending pins 16, the spacing or radial positioning and length of which may vary depending upon the kind and size of riiling. These pins are frictionally held in xed position, as shown more clearly in Fig. 4, by means of the threaded bolt 17 engaging the elongated sleeve 18. As shown, the pins 16 (one of which is shown in dotted lines) are held by means of the surface 19 applied against the peripheral surface 21 of the pins to hold the latter frictionally against outward radial movement relative to thecoupling member 22. Preferably, as indicated, the pins to aid their positioning are nested within the rounded surface 23 of the said coupling member.

It must be understood that as the barrel is placed over the liner with the tool 11 in the liner in the axial positioning of Fig. l, the pins 16 constitute the initial contact with the rifling 7 of the barrel 1, since it will be noted that they project slightly beyond the respective outer they engage the barrel rilling 7 and of course concurrently therewith the barrel is moving axially to receive the liner 4. Such combined axial and rotative movement of the barrel relative to the liner will continue until a second set of pins as immediately hereinafter described commence to function in theassembly operation as it proceeds.

Interposed between the threaded end portion Z7 of the alignment rod 11, the internally threaded spacer member 28 is provided having the end surface 29 for receiving in nested relation therebetween at 20, the said second set of pins 31. The latter extend radially as shown more clearly in the sectional view Fig. 5, but as more clearly indicated in Fig. 7 are positioned in different sectors relative to the periphery of the tool to accommodaterthe twist of the rifling. It will also be noted that as to construction the latter pins are provided with a raised surface forming a shoulder as at 32. They are intentionally made with such raised portion which extends in all cases parallel to the longitudinal axis of the barrel and liner assembly so that when the rifled sleeve attains the end abutting position within the barrel as at 33 (see Fig. 1), the pins 31 are then jointly engaging both the rifling in the liner as well as the riiling in the barrel simultaneously. By reason of such joint engagement of the barrel and liner rifling at the nal stage of assembly, unusual accuracy in the rotative positioning of the rilled liner with relation to the rifled barrel is assured. It will thus be clear that the raised face portions 32 of the pins 31 snugly engage the riing 7 of the barrel and the rilling 8 of the liner when such rifling is joined and becomes contiguous which occurs when the liner 4 is snugly shouldered against the surface 33 of the barrel 1. Since the pins 31 snugly engage the respective riliing of both liner and barrel such contiguity is positively assured.

It will now be understood that when it then becomes necessary upon completion of the liner-barrel assembly to separate the rod 25 from the outer portion 3S this is done by simply removing clamp 9 and releasing the tapered pin 34 -as shown more clearly in Fig. 4 by driving the latter outwardly of the engagement at 30 with the said elongated portion 35 of the alignment rod 11. In removing the clamp from the neck portion 40, the respective Allenhead screws 12 and 13 are loosened so as to enable the said separation and complete disassembly of the tool to occur. The liner is then in its desired final position in the barrel, the latter has cooled and the progressive twist riliing contiguously provided for.

It will of course be appreciated that the specic manner Y in which the assembly of the liner and the barrel takes place may vary as, for example, in the type and location of pms employed and the arcuate arrangement or posiltioning of such pins since this will depend largely upon vthe type or riing employed in the final product.

While the invention ,has been set forth only in a single p embodiment, it will be obvious that it is ,capable of other forms without departing from the-scope of the appended claims.

We claim: 1. In an alignment rod for effecting the assembly of a rilled liner with a ried gun barrel or the like, the combination `of an outer casing comprising a plurality of aligned hollow sections predeterminately connected to- Ngether, means for connecting said sections, radially extending pin means in spaced axial relation around the 4 longitudinal axis of the rod to permit engagement of at least one of said pin means simultaneously with the rifling of the barrel and liner when the latter members are positioned axially imminent to nal assembled relation of said liner and barrel.

2. In an alignment rod for assembling a rilied liner with a rifled gun barrel or the like, the rod having an outer elongated casing consisting of a plurality of aligned sections, an inner rod extending within the said sections and being axially fixed relative to one of the sections, a plurality of radially extending pins mounted on the casing in spaced apart relation relative to the longitudinal axis of the said casing with at least one of the pins in engagement with the barrel and liner rifling in the assembled position of the latter members, means mounted on the inner rod for connecting the inner rod and casing and removable clamping means on the said casing for predeterminately supporting the liner while inserting the liner within the barrel.

3. In an alignment rod for effecting the assembly of a rifled liner with a ried gun barrel or the like, the combination of an outer casing comprising a plurality of aligned hollow sections, means for connecting said sections together, radially extending pin means in spaced relation along the longitudinal axis of the rod, certain of the said pins being mounted in unlike arcuately disposed sectors relative to the other of said pin means and to rifled liner with a rifled gun barrel or the like, the combination of an outer casing comprising a plurality of aligned hollow sections connected together, means for connecting said sections, spaced-apart radially extending pin means in a plurality of planes along the longitudinal axis of the rod positioned at certain of the said connections of the said hollow sections with at least a portion of said pin means in engagement with the ring of the barrel and liner when the latter members are positioned axially imminent to nal assembly.

5. In an alignment rod for assembling a ried liner with a ried gun barrel or the like, the rod having an outer elongated casing consisting of a plurality of aligned sections, an inner rod extending within the said sections and being axially xed relative to at least one of the sections, a plurality of radially extending pins mounted on the casing for engagement by at least one of said pins simultaneously with the rifling of the said barrel and liner when the latter members are positioned axially imminent to final assembly, means cooperating with the inner rod for connecting the inner rod and said casing and clamping means on the said casing for predeterminately gripping the liner while inserting the liner within the said barrel.

6. In an alignment rod for assembling a ried liner with a rifled gun barrel or the like, the rod having an outer elongated casing consisting of a plurality of aligned sections, an inner rod extending within the said sections and being axially fixed relative to one of the sections, a plurality of radially extending pins in a plurality of planes mounted on the casing with at least one of the pins engaging simultaneously the riing of the liner and the barrel when the latter members are imminent to nal assembly, means engaging the inner rod for connecting the said inner rod and casing and means on the said casing for predeterminately gripping said liner in the course of making the assembly ,of the liner with the gun barrel.

7. In an alignment ,rod of the character described for effecting the assembly of a ried liner with a rilled gun barrel or the like, the combination of an outer casing comprising a plurality of aligned hollow sections connected together, combined pin and inner rod means for connecting said sections, radially extending pin means in spaced relation in a plurality of planes along the longitudinal axis of the rod with at least one of the pin means engaging simultaneously the riiling of the said liner and barrel when the latter members are positioned axially imminent to iinal assembled relation of the liner and barrel, the said pin means being removably mounted predeterminately relative to the said outer casing.

8. In an alignment rod for effecting the assembly of a ried liner with a ried gun barrel or the like, the combination of an outer casing comprising a plurality of aligned hollow sections connected together, means for connecting said section, a plurality of sets of radially extending pin means in spaced apart relation along the longitudinal axis of the alignment rod and being positioned to permit engagement of one set of said pins simultaneously With the rifling of the barrel and liner when the latter members are positioned axially imminent to final assembled relation of said liner and barrel.

9. In an alignment rod for assembling a n'fled liner with a ried gun barrel or the like, the rod having an outer elongated casing consisting of a plurality of aligned sections, an inner rod extending within the said sections and being axially xed relative to one of the sections, a plurality of radially extending pins mounted in a plurality of planes on the casing, at least one of the said pins simutaneously engaging the rilling of the said liner and gun barrel when the latter members are positioned axially imminent to linal assembled relation, means for connecting the inner rod and outer casing, clamping means for predeterminately supporting the liner while assembling said liner with the barrel, said means for connecting said inner rod and casing being predeterminately removable to- 6 gether with the said clamping means upon disassembly of said latter means.

10. The subject matter of claim 8, at least a portion of the said pins having heads formed to engage closely rifled portions of the rifling of the barrel and liner simutaneously upon predetermined axial positioning of the said barrel relative to the liner.

1l. The subject matter of claim 10, the said pins having attened side portions for said engagement of the heads with the said rilling of barrel and liner.

l2. In an alignment rod for assembling a ried liner within a rilled gun barrel or the like, the rod having an outer elongated casing consisting of a plurality of aligned sections, an inner rod member extending within the said sections and being axially iixed relative to one of the sections, a plurality of radially extending pins mounted on the casing arranged to permit engagement of at least one of said pins simultaneously with the rifling of the barrel and liner when the latter are positioned axially imminent in substantially final assembled relation of said liner and barrel, means on the said inner rod member for connecting the inner rod member and casing and clamping means on the said casing for predeterminately gripping the liner while assembling the latter member within the barrel.

References Cited in the le of this patent UNITED STATES PATENTS 1,448,528 Elliott Mar. 13, 1923 1,514,168 Morgan et al Nov. 4, 1924 1,772,692 Stevenson Aug. 12, 1930 

